Stencil sheet



" Reissued Sept. 22, 1931 UNITED STATES PATENT ore-ice SHALLGROSS COMPANY, OF PHILADELP DELAWARE No Drawing. Original No. 1,674,611, dated June 19, 1928, Serial No. 226,817, filed October 1'7, 192?.

Application for reissue filed June 19, 1630. Serial No. 462,394.

This invention, enerally stated, relates to stencil sheets and has more especial relation to 'a stencil sheet in which in contradistinc-.

tion to a porous base of soft Wax, there is ap- L8, plied thereto or impregnated thereupon a coating material or base having aty e im-.

pressible coating composed of seed ac or other lac as a base, combined with nitrated cotton and camphor gum, as a hardener and 1 binder commingled with castor oil as a tempering agent and sperm oil or the like to keep the stencil in usual condition. 7

The object of my novel present invention is in the provision of a novel stencil sheet 15 of the character above indicated in which a is to provide a novel stencil sheet of the character stated and aboveindicated inwhich there is used as a base for the stencil sheet seed lac or other suitable lac in combination with a solution of nitrated cotton as a hardener and binder commingled With. certain 'oils for the attainment of a much more efficient and stronger stencil sheet thereby overcoming the weakness of present day stencils,

stated coated or impregnated with a material composed of a suitable lac, nitrated cotton,

gum and a tempering agent, as cas-e camphor tor' oil.

A further object of the present invention as is well known now to the trade and uponv is to provide a stencil sheet of the character is to provide a stencil sheet of the character above stated, coated or impregnated with the materials above itemized in connection with sperm or other suitable oil to maintain the stencil sheet in pliable and usable condition.

The-invention consists of the novel stencil sheet hereinafter described and finally claimed. I

In carrying out the present invention I em- -ploy a base of open texture or porous material of any suitable character. This base I coat or impregnate with a solution calculated to overcome the weakness of present day stencil sheets. The material or composition whichI employ and from which excellent results "have been obtained is comprised of a base of seedlac or other suitable lac dissolved in alcohol; a solution of nitrated cottontreated with a suitable solvent including camphor gum, and castor and sperm orother suitable 0118.

The proportions of ingredients I prefer to employ in the novel coating or impre nation of a stencil sheet may be set forth, as ollows, to wit As a base I prefer to employ substantially six ounces of seed lac or other suitable lac dissolved in about approximately 1 to 10 parts of alcohol. To this solution I add substantially three ounces of nitrated cotton dissolved in about 100 parts of a suitable solvent, to which latter has been added substantially 1 ounce of camphor gum; It will be noted that camphor is a non-volatile solvent of nitrocellulose and the lac. To the solution thus prepared I add as a tempering agent substantially three ounces of castor oil. The camphor gum and the castor oil operate-as plasticizers for this base. Inbrder to provide pliability to the stencil sheet, I add to the ingredients above enumerated, approximatelyvfifty ounces of sperm or other suitable oil. The sperm oil operates to extend the mass of mixed lac, nitrated cotton, and other ingredients without being a solvent of the lac or nitrated cotton, and confers upon it the pliability and displace'ability necessary forthe stencilizing operatiol'nlso that the resultant stencil sheet: may have its coatingstencilized .or displaced for the passage of'the HIA, PENNSYLVANIA, A CORPORATION 01 printing ink. In this connection it may be noted that the said lac or otherlac is used as a base, and that the solution of nitrated cotton is usedas a hardener or binder, so that a much stronger stencil sheet is provided than heretofore, thus overcoming the weakness of present day stencil sheets.

. Suitable coloring matter may be added at any desired stage of the commingling of the above ingredients, such as a dye or carbon black, which may have'been previouslydissolved in the solvents employed, such as alcohol or in'a'common solvent of the solution.

The basic open texture, porous 0r bibulous paper employed may be coated with the composition above described in any suitable manner as by drawing one surface of said paper into contact with or floating it uponthe surface of said composition, and then if neces-v sary, removing or draining off any excess of the composition .or material bydrawiing the coated sheet over a taut wire or straight edge or the like, and the coated sheet then hung up to dry.

,There is in practice suflicient evaporation of the alcohol in about a half-'hours time to permit handling of the sheet, which when dry is ready for'use. For transportation, storage and handling, sheets of oil paper may be packed between the stencil sheets whose tackiness if present is hardly appreciable, the oil sheets beingpre'ferably removed before putting the stencil sheets to use.

My novel stencil sheet is highly economical of ink during the operation of producing stencil ,copiestherefrom, and there is'no necessity for blotting the-stencil copies or to interleave sheets therewith, as sometimes now' has to be done. The stencil copies can be handled at once without danger of smearing the ink thereon, and the stencil sheet preserves its original form, notwithstanding wrinkling, crumpling and rough handling, and it will be found to be elastic, and does not permanently stretch, nor do the fibres of the tissue base loosen or pull apart.

My invention is not limited to the exact proportions given, and within the scope of ener and binder, as will be understood by I the ap ended claims,various substitutes or equiva ents may be used for the base hardthose skilled in chemistry.

v I have found in practice, that by my novel stencil sheet made as above described, the coating remains throughout an extended period of time ractically unchanged, and

Y without preliminary moistening is capable of being removed or displaced, as by the blow of the type, of a writing machine, or by the pressure of a hand stylus, from or on the.

underlying foundation sheets, leaving the open texture fibres of'the latter practlcally intact for the support of the centers of loop letters. It will further be found thatthe spaces corresponding with the lines or the characters will be substantially clear of the 1. A stencil sheet adapted for conversion I into a stencil by impact of type thereon, comprising a paper sheet of open texture, porous material, having a ,type impressible coating thereon, consisting of a base of lac dissolved in alcohol, and having added thereto dissollved nitrated cotton, camphor gum, and 01 s.

2. A stencil sheet adapted for conversion into a stencil by impact of type thereon, comprising a aper sheet of open texture, porous material, aving a type impressible coating thereon, consisting of a base of lac dissolved in alcohol, and having added thereto dissolved nitrated cotton, camphor gum, castor oil and sperm oil. l

3. A stencil sheet adapted for conversion into a stencil by impact of type thereon, comprising a paper sheetof open texture, porous material, having a type impressible coating thereon, consisting of a base of six ounces of lac dissolved in alcohol, and having added thereto about three ounces of dissolved nitrated cotton and about one ounce of cam phor gum, and fifty-three ounces of oils.

4, A compositionforcoating or impregnating a stencil sheet, which consists of a. base having a type impressible coating including seed lac dissolved in alcohol, dissolved nitrated cotton and camphor gum, a tempering agent of castor oil, equal in weight to said nltrated cotton, and a greater quantity of sperm oil.

5. A composition for coating or impreg nating a stencil sheet which consists of about six ounces of seed lac dissolved in about one to ten parts of alcohol, about three ounces of dissolved nitrated cotton dissolved in one hundred parts of a solvent, one ounce of camphor gum, a tempering agent of about three ounces of castor oil, and about fifty ounces of sperm oil.

6. A stencil sheet adapted for conversion into a stencil by impact of type thereon, commixture of lac and nitrated cotton in quantity not greater than the quantity of lac and cotton, and a larger quantity of liquid extending agent than the quantity of lac, ni- 5 trated cotton and non-volatile solvent, said extending agent being a non-solvent for the cotton and lac. 1

8. A stencil sheet adapted for conversion int-o a stencil by impact of type thereon, comprising a paper sheet of open texture, porous material, having a type impressible coating thereon, consisting of a mixture of lac, a quantity of ni trated\ cotton less than the quantity of lac, a non-volatile solvent for the mixture of lac and cotton in quantity less than the combined quantity of lac and cotton, and a liquid extending agent in quantity greater than the combined quantity of lac and cotton, said extending agent being a nonsolvent for the cotton and lac.

9. A stencil sheet adapted for conversion into a stencil by impact of type thereon, com prisinga sheet of open texture, porous material havlng a type-impressible coating thereon consisting of a mixture of lac, nitrocellulose, a plasticizer which is a solvent for the nitrocellulose and lac, and a liquid extending agent which is not a solvent for the nitrocellulose and lac.

In testimony whereof, I afiix my signature HERBERT L. SHALLCROSS. 

